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High life history diversity within a single genus of algal viruses
No full textMicrobial viruses are key players in aquatic ecosystems, where they control host populations and affect nutrient flow. The impact of these viruses can be understood through their life history traits, which are used to parameterize ecological models and infer evolutionary strategies. However, most existing data on microbial virus traits come from highly divergent strains. Very little is known about the trait diversity of closely related viruses, opening the critical question: can unknown viral traits be extrapolated from those of known strains? To answer this question, we quantified the life history diversity of related aquatic microbial viruses in unprecedented detail. We measured nine life history traits in 34 strains belonging to the phytoplankton-infecting genus Chlorovirus. Chloroviral traits varied 5- to 77-fold across strains, in some cases rivaling the known trait range for all phytoplankton viruses. Contrary to expectations, only specific infectivity was predictive of viral growth and there was no evidence of life history trade-offs. Our results suggest that more detailed studies of viral diversity could change our understanding of their function in aquatic ecosystems. More broadly, we show that known virus strains may not be representative of their relatives.publishe
An Analysis of the Interplay and Mutual Benefits of Grounded Theory and Visualization
No full textGrounded theory (GT) is a research methodology that entails a systematic workflow for theory generation grounded on emergent data. In this paper, we juxtapose GT workflows with typical workflows in visualization and visual analytics (VIS), unveiling the characteristics shared by these workflows. We explore the research landscape of VIS to study where GT is applied to generate VIS theories, explicitly as well as implicitly. We discuss “why” GT can potentially play a significant role in VIS. We outline a “how” methodology for conducting GT research in VIS, which addresses the need for theoretical advancement in VIS while benefiting from other methods and techniques in VIS. We illustrate this “how” methodology with a use case of adopting GT approaches in studying visualization guidelines.publishe
Wege von Lehrerinnen und Lehrern im Berufsverlauf
No full textDieser Beitrag thematisiert den Berufsverlauf von Lehrpersonen vom Berufseinstieg nach der Erstqualifikation bis zum Austritt aus dem Beruf. Entwicklungsverläufe und Übergänge samt Herausforderungen und Brüchen werden thematisiert. Fragen des beruflichen Lernens als bedeutsamer Teil der Professionalisierung insgesamt finden Berücksichtigung.publishe
Towards Finding Hay in a Haystack : Explicit Tensors of Border Rank Greater Than 2.02m in C<sup>m</sup>⊗C<sup>m</sup>⊗C<sup>m</sup>
No full textpublishe
An Automata-theoretic Basis for Specification and Type Checking of Multiparty Protocols
No full textWe propose the Automata-based Multiparty Protocols framework (AMP) for top-down protocol development. The framework features a new very general formalism for global protocol specifications called Protocol State Machines (PSMs), Communicating State Machines (CSMs) as specifications for local participants, and a type system to check a -calculus with session interleaving and delegation against the CSM specification. Moreover, we define a large class of PSMs, called “tame”, for which we provide a sound and complete PSPACE projection operation that computes a CSM describing the same protocol as a given PSM if one exists. We propose these components as a backwards-compatible new backend for frameworks in the style of Multiparty Session Types. In comparison to the latter, AMP offers a considerable improvement in expressivity, decoupling of the various components (e.g. projection and typing), and robustness (thanks to the complete projection).publishe
Many Eyes Together : Investigating the Perceptual, Cognitive, and Social Foundations of Collective Detection in Bird Flocks
No full textSocial information use is considered one of the key benefits of group living. For instance, in the context of predation, group members can rely on each other’s vigilance to detect approaching threats in a process known as collective detection. Despite the intuitive appeal of this hypothesis and extensive research on the topic, significant gaps remain in our understanding. Vision is expected to play a critical role in anti-predator vigilance, especially for species with wide visual fields, but the challenge of tracking and quantifying visual input has made it difficult to study. Additionally, detection itself has been historically hard to measure, often approximated through observable behavioral responses that may not accurately reflect the true timing of detection. Moreover, little is known about how information is transmitted across group members, how individuals cognitively interpret the behavioral cues of others and how these interactions scale to produce collective outcomes. This complexity is further compounded by the difficulty of distinguishing between detections based on individual perception versus social information.
To address these questions, this thesis adopts an interdisciplinary approach, moving beyond traditional behavioral ecology to integrate insights from sensory ecology, cognition, collective behavior, social learning, and technological innovation. Chapter 1 established the importance of visual ecology in vigilance by using advanced motion-capture technology to track fine-scale head movements. It revealed the relationship between visual input, vigilance and escape responses, and specifically that the pigeons’ first “foveation” (directing their high-acuity visual area) toward the predator cue could be used as a reliable proxy for detection in our system. Some evidence of social influence in escape responses was also observed. Chapter 2 explored gaze following, a widespread social cognitive trait, within a collective behavior context, to investigate how pigeons interpret subtle social cues in a group setting. This chapter demonstrated that pigeons follow the gaze of conspecifics, with the strength of their response increasing with the number of demonstrators. Chapter 3 integrated these findings using a Bayesian network-based diffusion model, adapted from social learning framework, to model information transmission during collective detection. It showed that pigeons used peripheral vision to monitor conspecifics' gaze orientation and detect predators, suggesting the role of gaze following to collectively detect predators. In addition to providing the first empirical evidence of gaze following as a functional mechanism in this context, these findings demonstrate that pigeons can interpret subtle social cues during collective vigilance. We propose that gaze following allows pigeons to acquire predator-related information early in the anti-predator response, enabling them to assess threats independently and make more informed decisions.
These results underscore the role of perception in the context of vigilance to acquire environmental and social information, and more particularly for accurately measuring detection. They also reveal how social cues are cognitively processed during predator detection, and how social information is used at the collective scale. Overall, this thesis highlights the value of an interdisciplinary approach in addressing long-standing questions about collective vigilance and the benefits of group living, while encouraging future research to integrate new perspectives and methodologies from additional fields.publishe
Breaking the Degeneracy between Warps and Radial Flows in External Galaxies
No full textObservations of the line-of-sight (LOS) component of emitter velocities in galaxies are valuable for reconstructing their two-dimensional (2D) velocity fields, albeit requiring certain assumptions. A common one is that radial flows can be neglected in the outer regions of galaxies, while their geometry can be deformed by a warp. A specular approach assumes that galactic disks are flat but allows for the presence of radial flows. This approach enables the reconstruction of 2D velocity maps that encompass both the transversal and radial velocity fields. Through the study of velocity fields in toy disk models, we find that the presence of warps is manifested as a dipolar correlation between the two velocity components obtained by assuming a flat disk. This shows that the analysis of angular velocity anisotropies provides an effective tool for breaking the degeneracy between warps and radial flows. We have applied these findings to the analysis of velocity fields of the galaxies from the THINGS sample and M33. Many of these galaxies exhibit such a dipolar correlation, indicating the presence of warps. However, we have found that the warp alone cannot explain all variations in the velocity field, suggesting that intrinsic perturbations are common. Furthermore, we have observed that the spatial distribution of the LOS velocity dispersion may correlate with both velocity components, providing independent evidence of nontrivial velocity fields. These findings offer a robust approach to reconstructing the velocity fields of galaxies, allowing us to distinguish between the presence of warps and complex velocity structures by assessing their relative amplitude.publishe
The impact of childhood maltreatment on treatment outcomes for posttraumatic stress symptoms and aggression in male former combatants using narrative exposure therapy [NET] : results from a RCT in Eastern democratic Republic of Congo
No full textObjective
This study investigates the impact of childhood maltreatment on treatment outcomes among male ex-combatants in a randomized controlled trial (RCT) of Narrative Exposure Therapy for Forensic Offender Rehabilitation (FORNET), a specialized psychotherapy used to treat trauma sequelae including symptoms of posttraumatic stress disorder (PTSD), compared with treatment as usual (TAU). Specifically, we aim to compare former child and adult male soldiers who experienced childhood sexual abuse (CSA) with those who did not.
Methods
We conducted a sub-analysis of data from Koebach et al. [J Consult Clin Psychol. 2021], focusing on a sample of male former soldiers in the eastern Democratic Republic of Congo (DRC). Participants were categorized into two groups based on their history of CSA. Outcome measures included the prevalence of lifetime sexual assaults, perpetration of sexual violence against others, appetitive aggression, current violent behavior, symptoms of PTSD and depression and responses to two treatment modalities: TAU and FORNET.
Results
The group with a history of CSA had significantly higher rates of re-experiencing sexually assaults, especially by superiors, and of perpetrating sexual assaults against others. In addition, this group presented elevated baseline scores in all outcomes (appetitive aggression, current violent behavior, symptoms of PTSD and depression). Regarding effectiveness of treatment arms, the FORNET group demonstrated significantly greater reductions in appetitive aggression levels, PTSD symptoms and depressive symptoms compared to the TAU group, with no difference in treatment effectiveness between participants with and without a history of CSA. However, individuals with CSA showed statistically superior improvements in current violent behavior, with similar score levels to those without CSA after 6–9 months.
Conclusion
CSA among former soldiers was significantly associated with a higher prevalence of PTSD and increased risk of both sexual revictimization and the perpetration of sexual and other violent acts. FORNET demonstrates effectiveness in reducing appetitive aggression, PTSD symptoms, and violent behavior even in the subgroup highly affected by CSA - showing an even greater impact on current violent behavior. The ability of NET to address trauma and perpetration in a chronological sequence and adapt to the specific challenges of CSA likely account for its effectiveness in treating this complexly traumatized population, ultimately contributing to a reduction of violence in post-conflict communities. Special attention should be paid to revictimization during the rehabilitation process of ex-combatants.publishe
Cultural Appropriation : Wrongs and Rights
No full textFrom the fashion label Dior being accused of cultural appropriation after using American Indian imagery in an ad campaign for its “Sauvage” fragrance, to the backlash against Kendall Jenner’s afro-esque hairstyle in Vogue, debates about cultural appropriation have reached a fever pitch. In this much-needed analysis of the phenomenon Aurélia Bardon and Jennifer Page step back and ask: when is cultural appropriation wrong and when are we right to criticize it?
Their analysis of wrongful cultural appropriation centers on three questions: whether appropriation involves theft; whether it communicates disrespect; and whether it disregards requests made by marginalized groups about their cultural practices. Sometimes, they argue, it is structural injustice rather than individual wrongdoing that is at stake. They examine cultural appropriation’s political dimensions, asking whether the state should be neutral between appropriative and non-appropriative artistic expression. They contrast bans on wrongful cultural appropriation and the state’s using its expressive power as a speaker, spender, and educator to discourage it. They also consider the ethical questions that arise when cultural appropriation debates spur further debates about online shaming and cancel culture.
Using cases from music, fashion and the arts, Cultural Appropriation: Wrongs and Rights will be of great interest to students and researchers in philosophy, politics and related subjects, such as race and ethnic studies, sociology, and cultural studies.publishe
Bonobos tend to behave optimistically after hearing laughter
No full textEmotions mediate a wide range of cognitive functions, including memory, attention, and decision making. Studies of emotion in non-human animals have typically focused on negative emotions—like fear—that have clear behavioral correlates (e.g., freezing or retreating). To address this one-sided treatment of affect, we used a cognitive bias test to ask whether vocalizations associated with positive affect lead apes to expect positive future outcomes. All great apes produce laughter-like vocalizations during play that likely evolved from a shared ancestral form of laughter. We primed bonobos with conspecific laughter and then asked whether they were more likely to treat an ambiguous stimulus as if it were positive. Subjects ( n = 4) were first trained to approach rewarded (black) stimuli and skip unrewarded (white) stimuli. We then presented occasional ambiguous (grey) stimuli. Bonobos approached ambiguous stimuli to search for rewards more often after hearing laughter. Our results suggest that hearing laughter induces positive emotions and may thus bias bonobos’ decision making, including foraging or search behavior. While only apes produce human-like laughter, several other non-human animals have contagious play vocalizations. These vocalizations may lead other animals to anticipate positive outcomes, revealing commonalities in the role of positive emotion in behavior and cognition across species.publishe